Conventionally, a bi-fold door, in which end faces which are positioned at one end in the width direction of two doors with a rectangular plate shape are bendably joined, and outer surfaces of these doors are folded in a V shape so as to open an opening part, is, for example, used in the entrances to lavatory units for aircrafts.
Then, a handle for an opening and closing operation of the door is provided at a position on the outer surface near the bendably joined end faces.
However, in a conventional handle structure, there is a problem in that it is difficult to intuitively understand whether to push or to pull the bendably joined portion of the bi-fold door simply by looking at the handle.
In addition, depending on the form of the handle, it may be difficult to see whether or not there is a handle. Furthermore, there is also a problem in that either right-handed people or left-handed people may not understand the direction for inserting the fingers with respect to the handle at a glance.